An array substrate is a necessary component of a display panel such as a liquid crystal display (LCD) panel, etc. Generally, an array substrate is provided with a base substrate, on which thin film transistors, scan lines, data lines, pixel electrodes, a passivation layer, and a black matrix are formed. A gate and a source of each thin film transistor are connected to the scan line and the data line, respectively, and a drain of the thin film transistor is connected to the pixel electrode. In an array substrate, regions where the pixel electrodes are located are used for display, and are thus used as light transmissive regions; regions where the thin film transistors between the pixel electrodes, the scan lines, and the data lines are located cannot be used for display, and are thus used as shading regions, it is necessary to provide a black matrix in the shading region to avoid decrease in image contrast. Therefore, during fabricating process, the step of providing a black matrix layer will be additionally added to the fabricating process.
In addition, when fabricating the source and the drain, copper is usually used as the material of the source and the drain. A phenomenon that copper atoms diffuse into an active layer is likely to occur when the copper is in contact with the active layer, which reduces the performance of the active region. In particular, in a case where polysilicon is used as the material of the active layer, copper diffusion is even more obvious. In order to prevent the copper atoms from diffusing, a titanium layer, which located between the copper layer and the active layer, is further provided at the positions of the source and the drain.